The Astrology of Space - Matrix Software

The Astrology of Space
O-Associations
Astronomer V. A. Ambartsumian describes O-
Associations as:
"... [S]tellar systems where the partial density of 'O-
B2' stars is larger than the average field density of
these stars in such a way that this difference cannot
be explained by chance fluctuations; moreover, 'O' or
'BO' stars are present. The properties of O-
associations may be described as follows:
• (a) The linear diameters range between 30 and
200 parsecs.
• (b) The associations contain an open star
cluster of type "O" as nucleus.
• (c) They include, besides O-B2 stars, also
stars of types later than B2, sometimes even
Wolf-Rayet stars (though it is difficult to
ascertain the number of faint stars).
• (d) Sometimes multiple star systems of
Trapezium type and star chains may be part of
the nuclei,
• (e) hot stars occur also outside the nuclei.
• (g) There are reasons for presuming the O-
associations to be unstable systems."
The Associations have also been called aggregates
and groups, but the lack of basic data on individual
members of the associations or groups often resulted
in a specific system receiving a completely different
and independent description, which produced
confusion among the identifications.
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